To get lots of water onto the bristles of a waterbrush, you simple continue pressing the water reservoir. Provided it still has water in it, of course! It sounds obvious, but I have got so carried away with painting, I failed to realize the water had run out.
The water will drip off the brush onto your paper (Photos 1 and 2). To avoid puddles of water on your paper, move the brush as you squeeze the reservoir (Photo 3).
When you're adding additional water to paint already on paper, be careful not to squeeze too hard or long, or you can end up with too much (Photo 4). If this does happen, use a corner of a clean cloth, or a dry brush, to soak up the excess water. With practice, you'll soon learn to judge how much water you're going to get.
To fill the water reservoir, hold it under a running tap or submerge it in a small container of water (such as a bowl or mug). It's even easy to do from a small bottle of water when you're painting outside, provided you don't mind splashing a bit.
